Woodworth, George Walter
McGraw-Hill, 1950
Buku Teks
Fry, Maxwell J.
Routledge, 1997
Buku Teks
edited by Benyamin Haggott Beckhart
Columbia Universary Press, 1954, 1956
Buku Teks
Thorne, W.J.
Oxford University Press , 1948
Buku Teks
Bradford, Frederick A.
Longmans, Green, 1932
Buku Teks